5-GHz Frequency Synthesizer With Auto-Calibration Loop

A 5-GHz frequency synthesizer for ZIGBEE(IEEE 802.15.4) was implemented. It consumes 13.5mW adopting CMOS Logic divider and robust VCO from process and temperature variation by body voltage control of current source. It incorporates an automatic capacitor-bank tuning loop to extend frequency tuning range. This synthesizer was fabricated in 0.18-um technology; it consumes 7.5mA at 1.8V and offers 100kHz-loop bandwidth and always -103dBc/Hz at an offset of 1MHz. the lock time is 30us. The PLL output tuning range is 14% from 2.258GHz to 2.614GHz